If the average ambient sound level exceeds 105 dBa, what must be used?

In environments where the average ambient sound level exceeds 105 dBa, visible notification appliances must be used to ensure that all occupants are alerted to a fire alarm. This is crucial because high ambient noise levels can significantly impede the effectiveness of audible alarms, rendering them ineffective for alerting individuals to an emergency.

Visible notification appliances, such as strobe lights or visual alarms, are essential in such scenarios as they provide a clear visual cue that is not affected by background noise. This ensures that individuals with hearing impairments or those who may be unable to hear the audible alarms due to the high noise level can still be notified of an emergency situation.

Using only audible alarms in such conditions could lead to dangerous situations where individuals do not receive adequate alerting, underscoring the importance of visible notification systems in maintaining safety in high-noise environments.